All of the electrical wire you use to wire up your entire kart does not count on your Bill of Materials. This is done by design so that karts do not skimp on wire size in an attempt to get their kart to fit the budget requirements. When you go to build and wire up a kart, please make sure the wire you select for each application is appropriately sized for the current you plan to flow through it. the guide on the American Wire Gauge below may be helpful to familiarize you with how wires are measured

American wire gauge (AWG)is a standardized wire gauge system used since 1857 predominantly in North America for the diameters of round, solid, nonferrous, electrically conducting wire. Dimensions of the wires are given in ASTM standard B 258. The cross-sectional area of each gauge is an important factor for determining its current-carrying capacity. Increasing gauge numbers denote decreasing wire diameters. That means the smaller the gauge number, the bigger the diameter.

Torque produced in an electric motor is proportional to the current (amps) it draws… more current (amps), more torque. That means you need thicker wire for more current. Typical amp capacity listed here.

An inexpensive source of wire is electric drier or range cords. Usually 6-8 AWG 3-4 wires per cord, 3+ feet long and it's easy to separate the individual conductors from the pigtail. They are often left on appliances when set out for trash.

the main current loop:

• out of your battery
• through the fuse
• through the disconnect
• into the motor controller
• back out of the controller
• and back to the battery

will generally benefit from the largest gauge wire you can comfortably use. 12AWG wire is unacceptable for this purpose. 10AWG wire can function in a pinch, but may get warm to the touch (less than ideal). 8AWG, 6AWG or even 4AWG or larger still is best.

It can be daunting at first to learn how to make the various connections between these wiring devices and a wire of such a large gauge, but it is worth learning how to use a crimping tool to crimp on the correct sized ring terminal to terminate these conductors to their respective devices throughout this loop.

Karts can quickly become jumbled with “low voltage” circuits. Connections for the Motor Controller Throttle, Reverse, Brake input, enable, and circuits to control headlights, taillights, a horn, a buck converter to run them all, current monitors, battery voltage monitors, blown fuse indicator, emergency beepers or BMS, etc. can quickly get out of hand, and can draw more current than you'd think.

Spec out the maximum current flow that each component in your design is going to see, and make sure to select a gauge wire that is designed to accommodate it. A rule of thumb:

The main Buck converter that accepts Battery VCC input and outputs a steady 12v or 24v for the low voltage/signaling circuits: 12AWG on input and output Headlights: 12AWG or 14AWG, unless you know your lamps are definitely lower current. even LED headlights can draw a fair current, and remember it's cumulative. Horn: 14AWG or 16AWG. Horns draw a fair bit of current but it's not a continuous load like headlights so it's not as big of a deal to oversize the wiring. Taillights/brake lights: 14AWG or 16AWG Signaling out of the motor controller: usually internally limited to 200ma or less so 22AWG or smaller is acceptable. do be aware that especially small wires (30AWG or so) can risk simple mechanical failure just from being jostled around on the kart during normal use.

Different electrical connectors are well suited to the specific purposes they are designed for. spent some time familiarizing yourself with different connectors as you design and build your first kart.

As mentioned briefly in the previous section, its unlikely you can finish building a kart without needing some sort of crimp connector in a circuit somewhere. crimp-on ring terminals are especially likely to be neede around your Regulation Fuse and your Main Disconnect. take special care to select the correct size terminals for these connections, crimp them correctly to the wires, and torque the terminals down fully.

The XT-60 series of connectors are a reasonable, cheap option for getting a first kart off the ground. They are designed to be soldered to large gauge stranded wire and generally stay connected unless pulled apart by hand. the indicated xx section of the XT-xx part number is the amperage the connector is good for; XT-30, XT-60, and XT-90 connectors are available. XT-60 connectors have been known to get warm to the touch in karts before, so it's generally recommended to use the XT-90 size for your main connection to your battery. XT-60s are acceptable for smaller currents like a buck converter or field coil on an alternator.

NB: If you do not have a large-tip iron, soldering these, especially with stranded wire (you are using stranded wire, right?) will be a bear. Pay attention to how your solder is flowing to ensure the bond you create between the wire and the connector will handle the current you will run through the connector. cover with heat-shrink before use. You can overheat the plastic in these connectors which will allow for the pins to deform position, risking poor connection and thus heat/failure in the field. use a 70W iron or better. the 25W special from Walmart will not cut it.

XT series connectors cannot be plugged in with reverse polarity, which is especially beneficial in protecting your kart, batteries, and chargers.

Anderson Powerpoles are a fine connector to use for your battery/motor load carrying circuits. They work best with the proprietary crimping tool, but can be crimped with a standard crimper in a pinch. Good sources for powerpoles are eBay, Amazon, and Powerwerx.

Make sure to order the right size for your amperage needs!

Check out the Anderson Powerpole Connector General Installation Tips

Like the XT series connectors, Andersons also cannot be accidentally connected with reverse polarity, especially useful for batteries.

The 221-41X series of connectors from the Wago company are a robust lever-nut style connector which boast an rating of up to 32Amps, accepts a wide range of wire gauges (12AWG to 24AWG on paper and even as small as 30AWG in practice, especially if the end is doubled up or ferruled) in solid and stranded, making it a useful option for quick, no-nonsense connections throughout your kart. unlike screw-on wirenuts the lever-style connector clamps in place against the wire so normal jostling from operating the kart will not typically sever the connection.

the Wago company also makes, a larger connector, the 221-61X type experience in the league generally motivates us to recommend against using them as a long term option for your highest current connections (in that main battery loop, on motor phase wires, etc) the 221-61X series of connectors are a decent “back pocket” solution to quickly fix a severed wire in the field (during an endurance race, for example) but plan on a more permanent solution in your designs. these connectors have melted and deformed some from current flow in these applications. to connect wires larger than the recommended gauge for the connector (221-615 Wagos are rated for 10AWG maximum) the stranded conductor can be stripped back and inserted into multiple locations and lever-locked into two positions at once, so none of the strands have to be cut to make the connection. Again this is not recommended for the long term.)

Terminal blocks are a long-standing standard in electrical connections at a variety of current levels, and are available in designs that accommodate different types of terminated and unterminated wires, including ferrules, ring terminals, fork terminals, all of which crimp on to the end of the wire before they are inserted into the block. Terminal blocks are especially useful for power distribution buses, where many many different wires all need to be connected together, like the 0VDC return/reference ground in your low-voltage system, the VCC/V+ in your low voltage system immediately out of your buck converter, or for example immediately after your headlights switch where multiple headlight lamps, and taillight running light lamps all need to be connected to the switched power.